Lymphatic system

Photo by: Matthew Cole

The lymphatic system is a network of vessels that transports nutrients to
the cells and collects their waste products. The lymph system consists of
lymph capillaries and lymph vessels that are somewhat similar to blood
capillaries and blood vessels. In addition, it includes lymph ducts (tubes
that carry fluids secreted by glands) and lymph nodes (reservoirs that
filter out bacteria and other toxins from the lymph that passes through
them).

In the circulatory system, blood flows from the heart, through the
arteries, and into capillaries that surround all cells. When blood reaches
the capillaries, a portion of blood plasma (the liquid portion of the
blood)
seeps out of the capillaries and into the space surrounding cells. That
plasma is then known as tissue fluid. Tissue fluid consists of water plus
dissolved molecules that are small enough to fit through the small
openings in capillaries.

Tissue fluid is an important component of any living animal. Nutrients
pass out of tissue fluid into cells and, conversely, waste products from
cells are dumped back into the tissue fluid.

Some tissue fluid returns to blood capillaries by osmosis. (Osmosis is the
process by which fluids and substances dissolved in them pass through a
membrane until all substances involved reach a balance.) But some tissue
fluid is also diverted into a second network of tubes: the lymphatic
vessels. Tissue fluid that enters this network is known as lymph. Lymph is
a clear, colorless, somewhat sticky liquid. The liquid formed in a blister
is lymph.

Words to Know

Capillaries:
Tiny vessels in the body that carry fluids such as lymph and blood.

Lymph:
A fluid that runs through the lymphatic vessels, lymph nodes, and other
lymphatic organs.

Lymphocyte:
A cell that functions as part of the lymphatic and immune systems by
attacking specific invading substances.

Lymph node:
Region of lymphoid tissue along lymph vessels that filters harmful
antigens from the blood and some tissues.

Osmosis:
Process in which fluids and substances dissolved in liquids pass
through a membrane until all substances involved reach a balance.

Movement of lymph

Tissue fluid passes out of the space between cells and through the walls
of lymph capillaries. Now called lymph, it follows a pathway back to the
heart that is somewhat similar to the venous system for blood. It passes
from lymph capillaries into larger tubes, the lymph vessels. Like veins in
the blood circulatory system, lymph vessels have valves that help push
lymph slowly back towards the heart. Eventually the lymph enters
a large collecting tube, the thoracic duct, located near the heart. From
the thoracic duct the lymph empties into the blood circulatory system
itself at the left subclavian vein.

The lymph system performs a second function also. Fats that have been
absorbed in the small intestine enter lymph vessels in that organ. Those
fats are then carried through the lymphatic system back into the blood
circulatory system.

Lymph nodes

At various points in the lymphatic system the lymphatic vessels are
enlarged to form structures known as lymph nodes. Lymph nodes serve four
primary functions. First, they remove from the lymph foreign particles
dumped into the tissue fluid from cells. Second, they produce a type of
white blood cell known as lymphocytes. Lymphocytes are major components of
the body's immune system, which fights disease. They occur

A macrophage (background) and a lymphocyte (fore-ground).
(Reproduced by permission of

Phototake

.)

in a variety of forms known as T cells (T lymphocytes) and B cells (B
lymphocytes). Third, lymph nodes are home to very large blood cells known
as macrophages. Macrophages attack and kill bacteria by surrounding them,
swallowing them up, and then dissolving them with enzymes. Fourth, lymph
nodes produce antibodies that are used to fight infections.

Lymph nodes are located in the armpit, neck, and groin. One symptom of an
infection is that lymph nodes become swollen with harmful material and can
be seen or felt.

Diseases of the lymphatic system

The uncontrolled growth of cells and tissues of the lymphatic system
result in a condition known as lymphoma, or lymph cancer. Lymphomas are
classified into two types, Hodgkin's or non-Hodgkin's. Both
forms can be fatal. Hodgkin's lymphoma, or Hodgkin's
disease, is marked by enlargement of lymph nodes, usually those in the
neck. Symptoms of Hodgkin's include chronic fatigue, depressed
immune function, weight loss, night sweats, and pain after drinking
alcohol. Hodgkin's lymphoma can be treated successfully and cured
with radiation or chemotherapy if it is caught in its early stages.
Although the cause of Hodgkin's is unknown, males, Caucasians,
people of higher socioeconomic status, the well-educated, and people with
certain blood types are more prone to develop it. For unknown reasons,
Hodgkin's most commonly affects people in their twenties or
seventies. People who work with certain chemicals, such as benzene and
rubber products, also seem to be more prone to develop the disease.

Several forms of non-Hodgkin's lymphoma have been identified. These
forms have little in common with each other. One example of a
non-Hodgkin's lymphoma is Burkitt's lymphoma, prevalent
among Central African children. Burkitt's lymphoma is characterized
by enlargement of the lymph nodes under the jaw. In contrast with most
lymphomas whose causes are unclear, Burkitt's lymphoma has been
linked to infection with the Epstein-Barr virus.

Symptoms for most lymphomas are similar. Many patients experience
enlargement of the liver and spleen as well as the lymph nodes. Some
patients have bloody stools or vomit blood. Tiredness, itching, weight
loss, fever, and general failure of the immune system may also be present.
These symptoms may diminish and intensify over several months before a
diagnosis is made. Sometimes, a bone marrow biopsy (test) is also
performed.

Treatment includes radiation or chemotherapy. Effectiveness of such
treatments varies depending on the severity of the lymphoma at the time of
diagnosis. Bone marrow transplants have been effective against some
lymphomas in advanced stages. The cure rate for non-Hodgkin's
lymphomas is generally poorer than for Hodgkin's lymphomas.

User Contributions:

Have developed lymphatic condition of left foot and ankle, which cauases fuild build up in lower part of leg. I might add that the foot has been operated on three times and ended with amputation of all my toes. I take diaretics for fuild problems anyway, but due to swelling on end of my foot, the surgical wound will not close. I currently use a compression stocking with silver as well perform treatments with inflatable system three time a day.
My question if any alternative medications can be used, or is this going to be a ongoing condition the rest of my life. A Physician stated that the possible cause was from trama to the foot from repeated operations?
Any suggestions would be healpful, as this disrupts my normal life.

My son has multiple swelling. Its seems to have started in the jaw, then that went away, then it is in his armpit, and that seems to have disappeared, and now its in the center of his chest plate. His groin nodes hurt as well. He sweats at night, is fatigued and very pale. He has an upset stomach too. This has been going on for over 3 months. I'm seriously worried it seems to travel in a path like pattern of swelling nodes. Has anyone heard of this?